METHOD AND SYSTEM FOR UPDATING AN ARCHIVE OF A COMPUTER FILE

• US 20100174685A1
• Filed: 03/16/2010
• Published: 07/08/2010
• Est. Priority Date: 03/01/2000
• Status: Active Grant

• Current Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Original Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Inventors: Forster, Karl D.
• Granted Patent: US 8,019,730 B2
• Time in Patent Office: Days
• US Class Current: 707/667
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 2201/83 the solution involving signatures

Abstract

A method and system for updating an archive of a computer file to reflect changes made to the file includes selecting one of a plurality of comparison methods as a preferred comparison method. The comparison methods include a first comparison method wherein the file is compared to an archive of the file and a second comparison method wherein a first set of tokens statistically representative of the file is computed and compared to a second set of tokens statistically representative of the archive of the file. The method further includes carrying out the preferred comparison method to generate indicia of differences between the file and the archive of the file for updating the archive of the file.

Claims

1. A method for updating an archive of a file to reflect changes made to the file, the method comprising:

selecting one of a plurality of comparison methods as a preferred comparison method, the plurality of comparison methods comprising;

a first comparison method wherein a file is compared to an archive of the file; and

a second comparison method wherein a first set of tokens statistically representative of the file is computed and compared to a second set of tokens statistically representative of the archive of the file; and

carrying out the preferred comparison method to generate indicia of differences between the file and the archive of the file for updating the archive of the file.

2. The method of claim 1, wherein the file is resident on a client computer, the archive of the file is resident on a server computer and the file is compared to a copy of the archive of the file resident on the client computer in the first comparison method, the method further comprising conveying the indicia of differences from the client computer to the server computer for updating the archive of the file.

3. The method of claim 1, wherein the indicia of differences comprises:

any data words that are different between the file and the archive of the file when the preferred comparison method comprises the first comparison method; and

any blocks of data words that are different between the file and the archive of the file when the preferred comparison method comprises the second comparison method.

4. The method of claim 2, further comprising:

prompting a user to select one of a first condition and a second condition as a selected condition for optimization in updating the archive of the file; and

selecting the preferred comparison method such that the selected condition is optimized.

5. The method of claim 4, wherein:

the first condition is efficient use of data storage on the client computer; and

the second condition is efficient conveying of indicia of differences from the client computer to the server computer.

6. The method of claim 2, wherein selecting the preferred comparison method comprises:

analyzing one or more conditions indicative of the preferred comparison method; and

selecting the preferred comparison method responsive to the conditions.

7. The method of claim 6, wherein one of the conditions is a bandwidth of a network connecting the client computer to the server computer.

8. The method of claim 6, wherein one of the conditions is a size of the file.

9. The method of claim 6, wherein one of the conditions is a type of the file.

10. The method of claim 2, wherein:

the copy of the archive of the file is resident on the client computer in a compressed form; and

the first comparison method comprises decompressing the copy of the archive of the file to generate a decompressed copy of the archive of the file and comparing each byte of the file to a corresponding byte of the decompressed copy of the archive of the file.

11. The method of claim 1, wherein:

the second set of tokens is resident on a client computer;

the archive of the file is resident on a server computer; and

the second comparison method comprises partitioning the file into a plurality of blocks, computing the first set of tokens statistically representative of the file by computing a cyclic redundancy code (CRC) value for each one of the plurality of blocks, and comparing each one of the first set of tokens to a respective one of the second set of tokens.

12. The method of claim 2, further comprising providing a network connection between the client computer and the server computer.

13. The method of claim 12, wherein the network connection comprises the Internet.

14. The method of claim 13, wherein the client computer is a portable computer.

15. A system for updating an archive of a file to reflect changes made to the file, the system comprising:

a comparison subsystem including;

a first comparator that, in operation, compares a file to a copy of an archive of the file, the copy of the archive of the file being resident on a client computer; and

a second comparator that, in operation, computes a first set of tokens statistically representative of the file and compares the first set of tokens to a second set of tokens statistically representative of the archive of the file on a server computer, the second set of tokens being resident on the client computer; and

a selection subsystem for activating a preferred one of the first comparator and the second comparator to generate indicia of differences between the file and the archive of the file.

16. The system of claim 15, wherein the file is resident on the client computer, the system further comprising a network interface responsive to the indicia of differences and configured to be coupled to the server computer to convey the indicia of differences from the client computer to the server computer.

17. The system of claim 15, wherein:

the copy of the archive of the file is resident on the client computer in a compressed form; and

the first comparator, in operation, decompresses the copy of the archive of the file to generate a decompressed copy and compares each byte of the file to a corresponding byte of the decompressed copy.

18. The system of claim 15, wherein the second comparator, in operation, partitions the file into a plurality of blocks, computes the first set of tokens of the file by computing a cyclic redundancy code (CRC) value for each one of the plurality of blocks and compares each one of the first set of tokens to a respective one of the second set of tokens.

19. The system of claim 15, wherein the selection subsystem comprises a user interface for prompting a user to select one of a first condition and a second condition as a selected condition, the selection subsystem selecting the preferred one of the first comparator and the second comparator such that the second condition is optimized.

20. The system of claim 16, wherein the selection subsystem includes a condition analysis subsystem responsive to one or more conditions indicative of the preferred one of the first and second comparators to select as the preferred one of the comparators.

21. The system of claim 20, wherein one of the conditions is a bandwidth of a network connecting the client computer to the server computer.

22. The system of claim 20, wherein one of the conditions is a size of the file.

23. The system of claim 20, wherein one of the conditions is a type of the file.

24-68. -68. (canceled)

69. A system for updating a remote archive of a locally stored file, comprising:

a byte differencing engine operable to generate a first indicia of differences between individual bytes of a current version of a file and a local copy of an archive of the file;

a block differencing engine operable to generate a current token set based on the current version of the file and an archive token set based on the archive of the file and to generate a second indicia of differences between the current version and the archive version based on the current token set and the archive token set;

a user interface operable to prompt a user for a selection of one of an efficient data storage condition and an efficient transmission condition for optimizing an update of the archive of the file; and

a selector operable to automatically select based on the selection of the user of a preferred one of the byte differencing engine and the block differencing engine to generate the respective one of the first and second indicia of differences.

70. A method for updating an archive of a file, comprising:

selecting one of a byte differencing engine and a block differencing engine; and

generating indicia of differences between a file and an archive of the file using a selected one of the differencing engines for updating the archive of the file.